Definition - What does Inoculum mean?
Inoculum refers to an active primary material used to refine grains in a cast macrostructure in order to protect a substrate's metallic surface.
Corrosionpedia explains Inoculum
Inoculum is a unit grain refiner that is used to implement grain boundary strengthening of metallic substances. It is applied with a wide variety of techniques depending on the substrate type to be protected.
Nucleation is the most widespread method used to infuse inoculum with metals. An example of such particles that are introduced as nucleants is Al-5%tI. After nucleant introduction, solute particles and grain refiners are added. These additive substances provide increased durability to the intergranular structure of the metal to be reinforced and limit the growth of dendrites.
The refinement of aluminum grain and/or its alloys enhances the mechanical properties of a casting and its surface finish.